Inconsistent Error Reporting: runc vs crun for Stopped Containers

[sohankunkerkar]

trafficstars

Description:

When attempting to kill a container that is not running, runc returns an error message indicating that the "container not running," while crun returns an error message stating "open pidfd: No such process." This inconsistency can lead to confusion for users who expect similar behavior from both runtimes.

Steps to Reproduce:

1. Create a container using either runc or crun.
2. Stop the container.
3. Attempt to kill the stopped container using the respective command.

Expected Behavior:

crun should return a consistent error message indicating that the container is not running when attempting to kill a stopped container.

Actual Behavior:

• runc Output:

Error: container not running

• crun Output:

open pidfd: No such process

xref: https://github.com/cri-o/cri-o/pull/8434

[giuseppe]

consistency with runc error messages is not a goal, but I agree the error could be improved. Would you like to open a PR to address it?